Heart massage apparatus

ABSTRACT

A cardiac massage apparatus and a drive system therefor are disclosed. The massage apparatus comprises a cup having a liner that is connected within the cup at its upper and lower ends. Dimensions defining an optimum cup shape as a function of ventricular length are disclosed wherein the heart remains within the cup when mechanically activated.

FIELD OF THE INVENTION

This invention relates generally to the field of cardiac assist devicesand more particularly, to devices of the type which pump the heart byemploying an externally applied force to obtain circulatory supportwithout contacting the blood.

BACKGROUND OF THE INVENTION

It has become common practice in the field of surgery to performcomplex, prolonged life-saving surgical procedures on the heart. Theseprocedures may include maintaining the circulation of transplantationcandidates and pumping for periods as long as several days by artificialmeans while a suitable donor heart is sought. Similarly, it is alsocommon practice for the surgeon to manually stimulate the heart to pump.However, this can only be maintained for short time periods on the orderof minutes, before the surgeon becomes fatigued.

In response to the above-noted need, alternative methods of pumping orassisting the heart to pump have been developed. For example, heart-lungmachines have been developed which actually circulate the blood througha pump and are commonly used in procedures such as coronary arterybypass, valve repair, and transitioning to other blood pumps. Theheart-lung machine is deficient as it is virtually impossible tocirculate the blood through a pump without causing damage to the bloodcells and blood born products which can result in post-surgicalcomplications such as bleeding, thrombi formation, and an increased riskof infection.

In response to the above noted deficiencies, an effort was made todevelop methods of pumping the heart which did not require directcontact between the pump and the blood. In general, these devicescomprise a device which wraps all or a portion of the heart and appliesa mechanical force that squeezes the heart in order to pump bloodthrough it.

These devices have a number of features in common. They usually comprisean outer cup of generally parabolic shape and include a flexible innermembrane, also of a similar parabolic shape which is connected to theouter cup along its periphery so as to create an air space therebetween.The outer cup includes an air inlet/outlet and a vacuum pump is utilizedto alternately impose a vacuum and to pressurize the air space. Thus,when the air space is pressurized, the membrane moves away from theouter wall and squeezes the heart, thus pumping blood and when thepressure is reversed, the heart is returned to the normal position, thusallowing blood to flow back into the heart to be pumped on the nextcycle.

However, the ventricular actuation cups described above are also notwithout their inherent drawbacks and deficiencies, as most, if not allof the devices taught in the prior art patents fail to give adequateconsideration to the basic fact that there is variability in the sizeand shape of the human heart. Thus, when these devices are used, theyexhibit one or more of a number of deficiencies. For example, if theshape of the heart does not closely conform to the shape of the cup, theventricles can become dislodged from the cup resulting in trauma to theheart muscle and inefficient pumping of the ventricle which isexacerbated the longer the cup is used. Also, if the lip, or flange, ofthe cup which maintains the seal is "constricting" or "too tight", thiscan result in trauma to the heart in areas of constriction. Similarly,prior art devices utilize inadequately controlled ventricular pumpingpressures which do not adequately or reliably empty both chambers of theheart. This frequently results in inadequate blood flow from eitherineffective left or right chamber pumping, or pulmonary edema caused byineffective pumping of the left chamber or ventricle thereby allowingblood to accumulate in the lungs.

With the foregoing in mind, it is an object of the present invention toprovide a heart massage apparatus that reliably and efficiently pumpsthe heart muscle.

Another object of the present invention is to provide a heart massageapparatus that effectively retains the heart within the cup.

Still another object of the present invention is to provide a heartmassage apparatus that minimizes trauma to the heart muscle while it isbeing pumped.

Yet another object of the present invention is to provide a heartmassage apparatus that substantially eliminates trapping of blood in thelower chambers of the heart or in the lungs.

SUMMARY OF THE INVENTION

These and other objects are achieved by providing an improved cardiacmassage cup comprising a cup shaped member of rigid material which isadapted to fit loosely over the lower portion of the heart. A liner offlexible material is contained within the cup shaped member and isconnected thereto at its upper end a predetermined distance from theapical section and its lower end is similarly connected to the cupshaped member a second predetermined distance from the basal section,thus leaving the middle part of the liner free from the cup shapedmember to form an annular diaphragm which contacts the ventricularsurface of the heart.

A first inlet is provided and communicates with the space between thediaphragm and the cup shaped member. The inlet is adapted to receivealternately applied relatively high positive and negative air pressuresto provide systolic and diastolic effects on the heart. A second inletmeans communicates with the interior of the cup shaped member and isadapted to receive a vacuum for holding the cup shaped member inposition on the heart. A first pressure transducer measures the pressurewithin the space between the liner and the cup shaped member and asecond pressure transducer is provided for measuring the vacuum holdingthe cup shaped member on the heart.

BRIEF DESCRIPTION OF THE DRAWINGS

Some of the features and advantages of the invention having briefly beenstated, others will appear from the detailed description which follows,when taken in connection with the accompanying drawings in which--

FIG. 1 is a perspective view of the heart massage apparatus of thepresent invention being inserted over a heart.

FIG. 2 is a perspective view of a heart massage apparatus of the presentinvention in place on a heart.

FIG. 3 is a perspective view of the heart massage apparatus of thepresent invention in place on a heart and illustrating the activation ofthe apparatus by a schematically shown control apparatus.

FIG. 4 is a sectional view of the heart massage apparatus of the presentinvention shown in the diastolic phase.

FIG. 5 is a sectional view of the heart massage apparatus of the presentinvention in the systolic phase.

FIG. 6 is a side view of the outer shell or housing of the heart massageof the apparatus of the present invention and showing the flexibleflange connected to the basal section of the cup.

FIG. 7 is a sectional view of the heart massage apparatus of the presentinvention in place on a heart in the diastolic phase.

FIG. 8 is a sectional view of the heart massage apparatus of the presentinvention in place on a heart in the initial portion of the systolicphase.

FIG. 9 is a sectional view of the heart massage apparatus of the presentinvention in place on a heart in the final portion of the systolicphase.

FIG. 10 is a sectional view of the heart massage apparatus according tothe prior art wherein the right ventricle has slipped out of the cupshaped member.

FIG. 11 is a graph representing the cup curvature shape for small,medium and large hearts.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

While the present invention will be described more fully hereinafterwith reference to the accompanying drawings, in which a particularembodiment is shown, it is to be understood at the outset that personsskilled in the art may modify the invention herein described while stillachieving the favorable results of this invention. Accordingly, thedescription which follows is to be understood as a broad teachingdisclosure directed to persons of skill in the appropriate arts and notas limiting upon the present invention.

In the discussion which follows, the detailed description of thepreferred embodiment is divided into two sections. In the first section,the cardiac massage cup 20 and the method of selection thereof, aredescribed in detail and the use of the cup 20 in combination with thedrive system is described thereafter in the section that follows.

CUP CONFIGURATION

As briefly mentioned, supra, in order for a cardiac massage apparatus tofunction optimally, a number of variables, including cup shape, appliedpressure and applied vacuum, must be properly tuned to a given heart.More particularly, as is known to those skilled in the art of medicine,the human heart is subject to variation depending on a number offactors, including age, sex, general health, and others. The discussionwhich follows is premised on a heart with ventricular chambers whoselong axis are of "normal" size falling within the range of approximately75 mm to 140 mm.

The ideal cup shape varies only slightly based on heart size; i.e., inthe direction of an ellipse formula (more blunted apex) for very largehearts, and more in the direction of a conical shape (more conical apex)for very small hearts (of length about 75 mm). It is, therefore, theintent of the invention to define a standard set of cups from which thesurgeon may select the proper cup for a particular heart, based on asingle measurement of the ventricular length L of the heart.

The cup shape for small hearts (75 mm or less) having a ventricularlength L is described by equation 1: ##EQU1##

The cup shape for average hearts (75 mm to 140 mm) having a ventricularlength L is described by equation 2: ##EQU2##

The cup shape for large hearts (greater than 140 mm) having aventricular length L is described by equation 3: ##EQU3##

The foregoing relationships are shown graphically in FIG. 11. With theforegoing in mind, reference is now made to FIGS. 4 through 6 whichdepict the cup in detail. The cardiac massage cup generally indicated at20 comprises a cup shaped member 30 and a liner 50 of flexible material.

The cup shaped member 30 defines a cavity having an apical section and abasal section and is adapted to fit loosely over the lower portion ofthe heart wherein the apex of the heart is positioned within the cupproximate the apical section 32 of the cup shaped member. Similarly, thebasal section or base 34 of the cup extends only as far as the atrialregion (i.e., to just below the atrium) of the heart. The cup shapedmember 30 has a greatest internal diameter D, an internal basal diameterd, an internal length between the apical section and the basal section Land a dimension AD that defines the distances between the apical sectionand the greatest internal diameter D. The foregoing parameters are thenused to define a cup of optimum shape for a heart of ventricular lengthL according to the following relationship:

D=0.96 L+/-0.05 L

d=0.90 L+/-0.05 L

AD=0.70 L+/-0.05 L

a=0.26 L+/-0.05 L

b=0.05 L+/-0.05 L

The cup shaped member 30 is constituted of glass, but could also be anmaterial (preferably translucent) which has adequate rigidity so that itdoes not collapse during diastolic actuation.

A liner 50 of thin flexible material is contained within the cup shapedmember 30 and is connected or bonded thereto with an adhesive such as"Silastic" adhesive at its upper end 52 a distance (a) from the apicalsection 32. The lower end of the liner 54 is connected to the cup shapedmember 30 a distance (b) from the basal section 34 thereof. The lowerend of the liner 54 may also be connected at the very end of the basalsection 34. Thus, the middle part of the liner 50 is left free from thecup member to form an annular diaphragm 56 which contacts theventricular surface of the heart. The liner 50 is molded or otherwiseprepared out of thin, plastic, translucent material, preferably anair-impervious silicone rubber elastomer such as the material sold bythe Dow Corning Company under the trade name "Silastic Q72213". Thissilicone rubber is widely used in biological applications and isgenerally recognized to be non-reactive with human tissue. The liner mayhave a thickness in the range of approximately 0.02 to 0.04 inch. Theliner is bonded to the inner surfaces as at (a) and (b) of the cup 30along its outer edges as shown in FIGS. 4 and 5. The shape of the linergenerally follows the curvature of the cup.

The cardiac massage cup also includes a first inlet means 60 adapted toreceive alternately applied relatively high positive and negative airpressures to the space between the diaphragm 56 and the cup shapedmember to provide systolic and diastolic effects on the heart. In theillustrated embodiment, the first inlet means 60 comprises a hollow sidearm adapted to communicate with the pressure system described in detailhereinbelow. The side arm 60 is preferably of material identical to thatof the cup shaped member and is fabricated simultaneously therewith. Inaddition, the side arm is angled toward the apical section 32 of the cupand protrudes a distance less than the maximum external diameter of thecup which assists in maintaining the operating field as small aspossible to minimize trauma to the patient.

A second inlet means or second inlet 70 adapted to receive a vacuum forholding the cup shaped member 30 in position on the heart and tocommunicate with the cavity defined by the cup shaped member is locatednear the apical end thereof. In addition, transducer means or pressuretransducers 80, well known to those skilled in the art are positionedproximate and preferably within each of the first and second inlet means60, 70 to measure the respective pressures induced therein.

A flange means or flange 90 of flexible material, again such as"Silastic" is connected to the basal section 34 of the cup shaped memberand extends around the periphery thereof. The flange 90 tapers inthickness as the distance from the cup increases and is also angledslightly inwardly at about 30 degrees or less toward the heart. Theflange assists in maintaining a vacuum seal between the heart and thecup, thus further minimizing the possibility of a ventricle slipping outof the cup.

It will be noted that throughout this specification, the fluid used toactuate the cardiac massage cup is "air". However, other fluids, such asliquid silicone, helium, carbon dioxide, water, or others could beemployed with equal efficiency.

Pressure Accessory System

FIG. 3 illustrates a pressure and vacuum system in schematic form whichcan be employed in connection with the improved cardiac massage cup 20.In the figure, reference character 100 designates, in block form, an airpump or pulsed pressure system of any suitable size and well known typeand of relatively high flow capacity capable of delivering pressures upto about 200 mm Hg. The air pressure is divided into a systolic source110 and a diastolic source 120, both of which are regulated usingregulators 125 to obtain a peak output in the average region of 120 to140 mm Hg. The systolic source 100 is output on line 115 and thediastolic source 120 is output on line 117, each of which areelectronically controlled, such as with an electronically programmedflow regulator 130 to adjust volume delivery at any instant of theactuating cycle, thereby controlling the liner at any instant of theactuating cycle. The distal end of line 140 is adapted to be pressurefit on to the free end of side arm 60. From the regulated systolic anddiastolic sources, the air under regulated pressure, as determined bythe particular massaging requirement, is delivered to the space betweendiaphragm and the cup to control the movement of the liner which in turnmassages the heart according to the particular massaging requirement.The forces are adjusted so that low pressures first empty the rightventricle (during the initial 50% of systolic actuation) and then emptythe left ventricle in the latter half of systolic actuation. The exactdegree of force required to accomplish right ventricle emptying (firsthalf of systolic actuation) and left ventricle emptying (second half ofsystolic actuation) are precisely delivered by the measurement of thepulmonary artery and systemic arterial pressures in the patient. Thedrive pressures are then adjusted to match the specific pressuresrecorded in any given individual. The pulmonary arterial and systemicarterial pressures can be measured by the placement of catheters 175,180 in the respective pulmonary and systemic arteries as shown in FIG.3.

The outputs of the pressure transducers 80 from the cup and those fromthe respective catheters 175, 180 are input to a pressure monitor 185that monitors the pressures and also produces an output signal that isrepresentative of the difference between the desired pulmonary andsystemic arterial pressures. This signal is then fed to an electronicprogrammer that controls flow regulators 130 to either increase ordecrease the output of the pulsed pressure source as needed to maintainthe desired blood pressure. Closed loop feedback systems of the typedescribed are well known to those skilled in the art and furtherdiscussion thereof is not deemed necessary.

Block 150 generally indicates a vacuum source or pump regulated byregulator 155 for producing a sustained negative pressure. The vacuum isoutput on line 160 to the second inlet 70 of cup 30 as shown. It isdesired that the negative pressure be the least amount that maintainscup attachment (generally less than 80 mm Hg.).

Using the System

When the surgeon determines that it is necessary to provide mechanicalassistance to the heart or to otherwise pump the heart by completelyartificial means, the surgeon need only measure the ventricular length Lor obtain a visual approximation thereof. A set of cardiac massage cupsof varying sizes is provided to the surgeon who selects the proper onefrom the set for use with a given heart. The cup 20 is then inserted onthe heart as shown. It is believed that it is sufficient to provide cupshaving ventricular lengths ranging from 75 mm to 140 mm in 5 mmincrements will be sufficient to satisfactorily fit virtually all thenormally encountered hearts.

Once the cup 20 is properly in place on the heart, the negative pressureis activated in line 160. The actual applied pressure is visuallyadjusted to the minimum which will retain the heart within the cup 20.

Next, the ventricular pressure is applied to the heart ventricles. Thegoal is to effectively empty the right ventricle (lower force) followedby the left (higher force) followed by dilating the ventricles byapplying a negative force to the surface of the heart. This isaccomplished by first applying during early systolic compressionapproximately 25-30 mm Hg. and during late systolic compressionapproximately 120-150 mm Hg. from systolic source 110. Similarly, duringthe diastolic phase of each cycle, pressures of approximately -100 to-120 mm Hg. are applied which are adjusted to a greatest negativepressure such that the diaphragm is in continuous contact with theheart.

The pressure measured by the transducer 80 in the side arm of the cupallows drive pressures to be appropriately adjusted to duplicate normalpulmonary and systemic pressures at early and late phases of systolicactuation, respectively. These pressures vary from patient to patient,however, they can easily be obtained from a given individual at the timeof cup attachment by use of standard techniques such as pulmonary andarterial catheters.

The use of the described cup transducers is important for properapplication of the direct mechanical ventricular actuation concept ofthe present invention. Since the right ventricle is the first chamber tobe emptied by cup actuation, drive pressures must be adjusted so thatthese actuating forces ar adequate for right ventricular actuationwithout being overly excessive. If the early forces of systoliccompression are to abrupt, the right ventricle will bulge despiteoptimal cup configuration described above. Finally, the pressures mustreach a maximal point which is slightly greater than the patientsarterial pressures in late systolic actuation to ensure adequateemptying of the left ventricle. Otherwise, blood will build up in thelungs and pulmonary edema will result.

A single actuation cycle is defined a the moment beginning at theinitiation of systolic actuation (positive pressures delivered in driveline 140) to the end of diastolic actuation (end of duration of negativepressure delivered in drive line 140). The cycle is generally dividedinto halves such that 50% of each cycle is spent in the systolic phaseand the remaining 50% is spent in the diastolic phase. The systolicphase of the actuating cycle is adjusted based upon the patient's bloodpressure while the diastolic phase is adjusted to ensure that a sealbetween the

liner and the heart is maintained. During the first 50% of the systolicphase, the pressures delivered to the first inlet 60 are adjusted so asnot to exceed the patient's measured pulmonary pressures, therebyavoiding right ventricle trauma and slippage. The latter 50% of thesystolic phase is then adjusted such that they are no more than 10-20%greater in magnitude than the patient's measured systemic arterialpressure. The diastolic phase of actuation is then adjusted to ensurethat the cup maintains a seal with the heart. This is done by graduallyincreasing the degree of vacuum (i.e., making the pressure morenegative) in line 140 to the maximal degree (most negative pressure)where the diaphragm does not separate from the heart. The separation ofthe diaphragm from the heart is easily detected by observing theconstant vacuum pressure measured in the second inlet 70. Any time thatthis pressure at inlet 70 drops (becomes less negative) indicates theseal between the liner and heart temporarily broke and, therefore, thediastolic actuation was too abrupt at that instant in the diastolicphase.

A transducer 80 in the apical port of the cup allows appropriate vacuumsto be utilized for cup attachment. The vacuum for cup attachment is setat the lowest degree of suction that maintains attachment as describedabove. The loss of attachment is clearly defined by any loss of negativepressure at the cup apex. Once the appropriate vacuum has beendetermined, continuous suction may be discontinued, and onlyintermittent suction is applied as needed based on any loss of negativepressure at the apex during actuation.

This tuning is critical to ensure the cup stays attached, particularlyduring the diastolic, or heart expansion phase. Otherwise, the heartwill not be actively dilated and the efficiency of the method will belost as the heart will dilate more slowly, and ventricular filling willbe decreased. This condition will result in decreased cardiac output andhemodynamic deterioration. Also, this tuning will allow the lowestdegree of vacuum utilization for cup attachment. Therefore, any traumathat results from use of excessive vacuum is eliminated.

It should be noted that the placement of the transducers within or nextto the cup side arm and apical port is critical for the aboveobjectives. Pressure transducers located anywhere else in the system donot measure real-time absolute pressures which are actuating the cup.Any change in drive line length, cup size or drive line connectors willchange the relationship between pressures measured at the drive systemand those that are directly acting on the cup and heart.

The foregoing embodiments and examples are to be consideredillustrative, rather than restrictive of the invention, and thosemodifications which come within the meaning and range of equivalence ofthe claims are to be included therein. Furthermore, the terms massageand actuate are used interchangeably to describe the pumping of theheart by mechanical means employing the cup of the present invention forvarious time periods ranging from short term (minutes) to indefinite(years).

That which is claimed is:
 1. A direct mechanical ventricular cardiacmassage apparatus comprising:a cup shaped member defining a cavityhaving an apical section and a basal section, said cup shaped memberhaving a greatest internal diameter (D) and an internal basal diameter(d), an internal length between the apical section and the basal section(L) and wherein the dimension (AD) defines distances between the apicalsection and the greatest internal diameter (D); a liner of thin flexiblematerial contained within said cup shaped member and being connected tosaid cup shaped member at its upper end a distance (a) from the apicalsection of said cup shaped member and wherein the lower end of saidliner is connected to said cup shaped member a distance (b) from thebasal section of said cup shaped member, the middle part of the linerbeing left free from said cup shaped member and forming an annulardiaphragm; means for alternately applying to the space between thediaphragm and the cup shaped member relatively high positive andnegative fluid pressures and; means including a vacuum for holding thecup shaped member in a predetermined position; said cup shaped memberbeing defined by the relationship:D=0.96 L+/-0.05 L d=0.90 L+/-0.05 LAD=0.70 L+/-0.05 L a=0.26 L+/-0.05 L b=0.05 L+/-0.05 L whereby when thecup shaped member is placed loosely over the lower portion of the heartso that the apex of the heart is positioned within the cup shaped memberproximate the apical section thereof and the basal section of the cupshaped member extends only so far as the atrial region of the heart, andthe middle portion of the liner that forms the annular diaphragm thatcontacts the ventricular surface of the heart, and wherein the means foralternately applying to the space between the diaphragm and the cupshaped member transfers pressure to the ventricular surface of the heartto provide systolic and diastolic effects on the heart, and the meansincluding a vacuum holds the cup shaped member in position on the heartthe optimum shape of the apparatus is defined for a heart of ventricularlength (L).
 2. A cardiac massage apparatus according to claim 1 and inwhich said means for holding the cup shaped member in position includesa vacuum source, and passageways extending from said source to theapical section and the interior of said cup shaped member.
 3. A cardiacmassage apparatus according to claim 1 and in which said means foralternately applying the relatively high positive and negative fluidpressure include a first inlet means in said cup shaped member at theposition of said diaphragm through which said fluid pressure areintroduced and a second inlet means proximate the apical portion of saidcup through which the vacuum for holding the cup shaped member in apredetermined position is introduced.
 4. A cardiac massage apparatusaccording to claim 1 and in which said means for alternatively applyingthe positive and negative fluid pressures is constituted of reservoirsof the high and low pressure controlled through a valve apparatus havingmoving parts for controlling the fluid through the valve, and meansincluding a timing device operated according to a predetermined timesequence for operating the movable parts of the valve in order tocontrol the application of these relatively high and low fluid pressuresto the diaphragm.
 5. A heart massage apparatus according to claim 3wherein said cup shaped member is constituted of a semi-rigid materialand wherein said first inlet means comprises a side arm extension intowhich said fluid pressures are introduced against said diaphragm.
 6. Aheart massage apparatus according to claim 5 wherein said side arm isangled toward said apical section and protrudes a distance that is lessthan the maximum external diameter of said cup shaped member.
 7. A heartmassage apparatus according to claim 1 further including a flexibleflange means connected to the basal section of said cup shaped memberand extending around the periphery thereof.
 8. A heart massage apparatusaccording to claim 7 and in which said flange means is tapered away fromthe cup shaped member and is angled toward said cavity.
 9. A heartmassage apparatus according to claim 7 and in which said flange means isparallel to the cup base and is angled toward said cavity.
 10. A heartmassage apparatus according to claim 7 and in which the angle oforientation of said flange means is less than about 30 degrees towardsaid cavity.
 11. A heart massage apparatus according to claim 3 furtherincluding a first pressure transducer means and a second pressuretransducer means for measuring the applied pressure positionedrespectively within said opening in said cup shaped member at theposition of said diaphragm and within said second opening proximate theapical portion of said cup.
 12. A heart massage apparatus according toclaim 1 and in which the cup shaped member is constituted of asemi-rigid material.
 13. A direct mechanical ventricular cardiac massagecup and comprising:a cup shaped member defining a cavity having anapical section and a basal section, said cup shaped member having agreatest internal diameter (D) and an internal basal diameter (d), aninternal length between the apical section and the basal section (L) andwherein the dimension (AD) defines the distance between the apicalsection and the greatest internal distance (D); a liner of thin flexiblematerial contained within said member and being connected to said cupshaped member at its upper end a distance a from the apical section ofsaid cup shaped member and wherein the lower end of said liner isconnected to said cup shaped member a distance from the basal section ofsaid cup shaped member, whereby the middle part of the liner is leftfree from said cup member to form an annular diaphragm; first inletmeans adapted to receive relatively high positive and negative fluidpressures applied to the space between the diaphragm and the cup shapedmember and; second inlet means adapted to receive a vacuum for holdingthe cup shaped member in a predetermined position, said cup shapedmember being defined by the relationship:D=0.96 L+/-0.05 L d=0.90L+/-0.05 L AD=0.70 L+/-0.05 L a=0.26 L+/-0.05 L b=0.05 L+/-0.05 Lwhereby when the cup shaped member is placed loosely over the lowerportion of the heart so that the apex of the heart is positioned withinthe cup shaped member proximate the apical section thereof and the basalsection of the cup shaped member extends only so far as the atrialregion of the heart, and the middle portion of the liner that forms theannular diaphragm that contacts the ventricular surface of the heart,and wherein the means for alternately applying to the space between thediaphragm and the cup shaped member transfers pressure to theventricular surface of the heart to provide systolic and diastoliceffects on the heart, and the means including a vacuum holds the cupshaped member in position on the heart the optimum shape of theapparatus is defined for a heart of ventricular length (L).
 14. A methodof provided cardiac massage using a cup shaped member defining a cavityhaving an apical section and a basal section which is adapted to fitloosely over the heart, the cup shaped member having a greatest internaldiameter (D), an internal basal diameter (d), an internal length betweenthe apical section and the basal section (L), and wherein the dimension(AD) defines the distance between the apical section and the greatestinternal diameter (D) and a liner of thin flexible material containedwithin the cup and being connected to the cup shaped member at itsrespective upper and lower ends, the middle part of the liner being leftfree from the cup shaped member to form an annular diaphragm which isadapted to contact the ventricular surface of the heart, and wherein asystem is provided for alternately providing to the space between theliner and the cup shaped member a relatively positive fluid pressure anda negative fluid pressure and a vacuum system for holding the cup shapedmember in position on the heart and comprising the steps of:measuringthe ventricular length (L) of the heart to be mechanically supported;selecting from a preselected set of cups, the cup most nearly satisfyingthe relationship:D=0.96 L+/-0.05 L d=0.90 L+/-0.05 L AD=0.70 L+/-0.05 La=0.26 L+/-0.05 L b=0.05 L+/-0.05 L inserting the selected cup shapedmember into the body cavity; positioning the selected cup shaped memberover the heart; applying a vacuum to the selected cup shaped member tomaintain the cup shaped member in position on the heart; applyingalternately to the space between the liner and the selected cup shapedmember a relatively positive fluid pressure and a negative fluidpressure; measuring the vacuum and the alternating relative positivefluid pressure and the negative fluid pressure; adjusting the vacuum andthe alternating relative positive fluid pressure and the negative fluidpressure to maintain the heart within the selected cup and to pump bloodthrough the heart.
 15. A method of mechanically pumping a human heart bydetermining the optimum shape of a direct mechanical ventricularactuation cup of the type having a cup shaped member defining a cavityhaving an apical section and a basal section,a liner of thin flexiblematerial positioned within the cavity having one end connected proximatethe apical section and its other end of the liner connected proximatethe basal section of the cup, the middle part of the liner being leftfree from the cup and forming an annular diaphragm; and furtherincluding a first inlet communicating with the space between thediaphragm and the cup and a second inlet communicating with the chambercomprising the steps of: (a) measuring the ventricular length (L) of theheart to be mechanically supported; (b) selecting a cup having theshape: ##EQU4## (c) placing the cup on the heart so that the apex of theheart is positioned proximate the apical section and the basal sectionextends only as far as the atrial region of the heart; (d) applyingalternately to the first inlet a relatively positive fluid pressure anda negative fluid pressure.
 16. The method according to claim 15 furtherincluding the step of feeding back to a control unit a signalrepresentative of the measured vacuum and a signal representative of thealternating relative positive fluid pressure and the negative fluidpressure.
 17. The method according to claim 16 further including thestep of utilizing the signal representative of the measured vacuum and asignal representative of the alternating relative positive fluidpressure and the negative fluid pressure to precisely measure andcontrol the vacuum and the pressure.
 18. The method of mechanicallypumping a human heart according to claim 15 further including the stepof applying to the second inlet a vacuum to hold the cup on the heart.